A conventional bearing assembly typically used in a gas turbine engine includes a split inner race mounted on a rotary shaft, a stationary outer race, and a plurality of bearing elements such as ball bearings supported therebetween and circumferentially spaced apart by a conventional cage. A plurality of circumferentially spaced apart splitline oil channels extend radially through the inner race at the splitline for channeling oil for lubricating the bearing elements and cooling the inner race. The splitline oil channels are typically provided with oil from a respective number of axial grooves disposed in the inner surface of the inner race, with each splitline channel being fed oil from a respective axial groove to ensure a continuous supply of oil uniformly around the inner race without any one splitline channel running dry.
The cage includes forward and aft surfaces spaced radially above respective portions of the inner race halves which may be typically lubricated by oil being channeled through radial holes in the inner race. Each of these radial holes is typically disposed in flow communication with a respective axial groove in the inner race for ensuring a continuous flow of oil therethrough.
In one advanced bearing assembly being developed, the bearing elements have a speed rating of about 2.3.times.10.sup.6 DN which is a very high speed requiring suitable lubrication to ensure a suitable life for the bearing assembly. Since this bearing assembly has a relatively large diameter, a relatively large number of splitline channels and radial holes are required to reduce the circumferential spacing between adjacent holes for more uniform lubrication and cooling of the bearing assembly. Furthermore, since the oil must be channeled past the splitline and splitline channels, suitable provision must be provided to ensure that the oil is not diverted by leakage through the splitline or flow through the splitline channels before being channeled to the radial holes. In an exemplary design, 24 splitline channels are being considered, along with 8 radial holes through each of the inner race halves for channeling oil to the respective cage forward and aft ends. Accordingly, conventional practice requires 40 axial grooves which would typically be circumferentially spaced apart on centers at about 9.degree.. This substantial number of axial grooves increase the cost of manufacture, reduces the contact area between the inner race and the shaft being supported thereby, and provides stress concentrations which must be recommended for ensuring suitable bearing life.